In a passive optical network (PON), severe intersymbol interference (ISI) may be caused by link dispersion and device bandwidth limitation at a high upstream rate.
A channel equalization technology is an existing technical means to suppress ISI of a communications system to ensure link performance. Apparently, the channel equalization technology can be applied to a high speed PON network to alleviate an ISI problem. However, different from a conventional continuous communication data mode, a PON network upstream burst mode has its particularity. That is, upstream data includes a plurality of discontinuous short-term burst blocks, and a channel characteristic of each burst block is different from a channel characteristic of another burst block adjacent to the burst block. Therefore, to equalize each short-term burst block, in an implementation process in the prior art, a length of a preamble of each short-term burst block needs to be extended, so that an optical line terminal (OLT) can extract the channel characteristic of each short-term burst block one by one based on the extended preamble, and perform corresponding channel equalization for each short-term burst block based on the channel characteristic.
In a process of implementing the present disclosure, the inventors find that the foregoing upstream data equalization method includes at least the following problem:
Because the preamble of each short-term burst block needs to be extended, the foregoing method undoubtedly consumes higher upstream overheads.